What is the Platonic cave?How is English literature influenced by this idea?

Plato, in The Republic, in an attempt to explain how we know something, drew on an extended metaphor ("The Allegory of the Cave") involving a cave wall, a fire (as a source of light), and figures moving past the fire and casting shadows on the cave wall. He compared these shadows to Man’s limited knowledge of the universe; we cannot perceive of the universe because our limited faculties, sight, etc., and our limited mental...

Plato, in The Republic, in an attempt to explain how we know something, drew on an extended metaphor ("The Allegory of the Cave") involving a cave wall, a fire (as a source of light), and figures moving past the fire and casting shadows on the cave wall. He compared these shadows to Man’s limited knowledge of the universe; we cannot perceive of the universe because our limited faculties, sight, etc., and our limited mental capacities (especially our ability to think beyond our perceptions) prevent us from understanding the universe, just as a viewer who saw only shadows would be very limited in understanding what a human being was, or what the world was outside the cave. The elaborate metaphor served thinkers well through the ages, from classical Greek times through the Renaissance, to today, as they tried to articulate the (literally) “unknowable,” not only as philosophers, but also as poets and artists of all media. Take for example, Wordsworth’s explanation in “Intimations of Immortality”—“our birth is but a sleep and a forgetting.” Here he tries to invoke Plato’s caveat against thinking our present “conscious” selves can figure out how the world works; he, like the whole “Romantic” movement, then goes on to suggest that Nature, in its beauty, rhythms, and seasons, might hold clues to the meaning of our lives, somewhat like Plato’s cave-shadows offer some, but not enough, clues to the universe’s secrets.